ERCP Procedure: What It Is, How It Works & What to Expect

ERCP for Bile Duct Stones: A Complete Patient Guide

ERCP (Endoscopic Retrograde Cholangiopancreatography) is one of the most important procedures in gastroenterology and hepatobiliary surgery. It combines endoscopy with X-ray imaging to diagnose and treat problems in the bile ducts and pancreatic duct — most commonly, the removal of gallstones that have migrated from the gallbladder into the common bile duct (CBD).

What Is ERCP?

ERCP is a procedure in which a flexible, lighted tube (endoscope) is passed through the mouth, down the oesophagus, through the stomach, and into the first part of the small intestine (duodenum). From there, the endoscope is used to access the bile duct and pancreatic duct at their opening into the duodenum (the ampulla of Vater).

The "retrograde" in ERCP refers to the direction of the procedure — the endoscope approaches the bile duct from below (from the intestine) rather than from above (from the liver). This allows the surgeon to:

• Inject contrast dye into the bile and pancreatic ducts for X-ray imaging
• Perform a sphincterotomy (a small cut to widen the bile duct opening)
• Remove stones using a balloon or basket
• Place stents to relieve bile duct obstruction
• Take biopsies of suspicious areas

When Is ERCP Needed?

ERCP is primarily used for therapeutic purposes — to treat problems rather than just diagnose them. The main indications include:

1. Common Bile Duct Stones (Choledocholithiasis)

The most common indication. Gallstones that migrate from the gallbladder into the CBD can cause:

• Jaundice (yellow skin and eyes)
• Dark urine and pale stools
• Right upper quadrant pain
• Acute cholangitis (bile duct infection)
• Gallstone pancreatitis

ERCP removes these stones non-surgically, avoiding the need for open bile duct surgery.

2. Acute Cholangitis

Bacterial infection of the bile duct from CBD stone obstruction. Urgent ERCP to decompress the bile duct is life-saving in severe cholangitis.

3. Gallstone Pancreatitis

When a gallstone obstructs the pancreatic duct, ERCP may be needed to remove the stone and relieve obstruction, particularly in severe pancreatitis.

4. Bile Duct Strictures

Narrowing of the bile duct from benign causes (post-surgical, primary sclerosing cholangitis) or malignant causes (cholangiocarcinoma, pancreatic cancer) can be diagnosed and treated with ERCP.

5. Biliary Stenting

Placement of a plastic or metal stent to relieve bile duct obstruction from cancer or strictures.

Before the Procedure: Preparation

Fasting

You must fast for at least 6 hours before ERCP (nothing to eat or drink, except small sips of water with medications). This is essential for safety — a full stomach increases the risk of aspiration during sedation.

Medications

• Blood thinners (warfarin, aspirin, clopidogrel): May need to be stopped 5–7 days before ERCP. Discuss with Dr. Patil.
• Diabetes medications: May need adjustment on the day of the procedure.
• Regular medications: Can usually be taken with a small sip of water.

Consent

Dr. Patil will explain the procedure, its benefits, risks, and alternatives. You will be asked to sign a consent form. Do not hesitate to ask any questions.

Allergies

Inform the team of any allergies, particularly to iodine or contrast dye.

During the Procedure: Step by Step

Sedation

ERCP is performed under conscious sedation (IV midazolam and pethidine or fentanyl) or general anaesthesia for anxious patients or complex procedures. You will be drowsy and comfortable but may not be fully asleep.

Positioning

You will lie on your left side or on your stomach on the X-ray table.

Endoscope Insertion

The endoscope is gently passed through your mouth. A local anaesthetic spray is used to numb the throat. You may feel mild pressure but should not feel pain.

Bile Duct Cannulation

The endoscopist guides a thin catheter through the endoscope into the bile duct opening. Contrast dye is injected and X-ray images (fluoroscopy) are taken to visualise the bile ducts and identify stones.

Sphincterotomy

A small cut is made in the sphincter of Oddi (the muscular valve at the bile duct opening) using an electrosurgical wire. This widens the opening to allow stone removal.

Stone Removal

Stones are removed using:

• Balloon catheter: A balloon is inflated in the bile duct and pulled back, sweeping stones out
• Dormia basket: A wire basket is opened in the bile duct to capture stones and pull them out
• Mechanical lithotripsy: For large stones (>15 mm), a crushing device breaks the stone into smaller pieces before removal

Confirmation

After stone removal, contrast is injected again to confirm complete clearance of the bile duct.

Duration

ERCP typically takes 30–60 minutes. Complex cases may take longer.

After the Procedure: Recovery

Immediate Recovery (0–4 Hours)

You will be monitored in the recovery area. Common sensations include:

• Mild throat soreness from the endoscope
• Bloating from air introduced during the procedure
• Mild abdominal discomfort

You will be able to drink fluids after 2–4 hours (once the throat numbness has worn off).

Discharge

Most patients are discharged the same day. You will need someone to drive you home — you cannot drive after sedation.

Diet After ERCP

• Day 1: Clear fluids and light foods
• Day 2 onwards: Normal diet (unless pancreatitis develops)

Activity

Avoid driving and operating machinery for 24 hours after sedation. Return to normal activities the following day.

Risks and Complications of ERCP

ERCP is a safe procedure in experienced hands, but it carries a small risk of complications:

| Complication | Frequency | Management |

|-------------|-----------|------------|

| Post-ERCP pancreatitis | 3–5% | IV fluids, pain management; usually mild |

| Bleeding from sphincterotomy | 1–2% | Usually self-limiting; rarely requires intervention |

| Cholangitis (infection) | 1–2% | IV antibiotics |

| Perforation | <0.5% | Rarely requires surgery |

| Contrast allergy | <0.5% | Antihistamines, steroids |

| Incomplete stone clearance | 5–10% | Second ERCP session |

Serious complications (requiring hospitalisation) occur in approximately 5–7% of cases. The risk is higher in patients with complex anatomy, large stones, or significant comorbidities.

ERCP Success Rates

ERCP successfully clears CBD stones in over 90% of cases in a single session. For large stones (>15 mm), mechanical lithotripsy achieves clearance in 95% of cases over 1–2 sessions. In the rare case where complete clearance is not possible, a biliary stent is placed to relieve obstruction while a second procedure is planned.

After ERCP: The Next Steps

Cholecystectomy After ERCP

ERCP treats CBD stones but does not remove the gallbladder — the source of future stones. Without cholecystectomy after ERCP, CBD stones recur in 10–15% of patients per year. Laparoscopic cholecystectomy is strongly recommended within 2–6 weeks of successful ERCP.

Follow-Up

A follow-up appointment with Dr. Patil is scheduled 2–4 weeks after ERCP to:

• Review the procedure findings
• Discuss the pathology report (if biopsy was taken)
• Plan cholecystectomy if indicated
• Address any ongoing symptoms

Frequently Asked Questions About ERCP

Q: Is ERCP painful?

A: No. ERCP is performed under sedation, so you will not feel pain during the procedure. Some mild bloating and throat discomfort afterwards is normal.

Q: How long does ERCP take?

A: 30–60 minutes for straightforward cases. Complex cases may take up to 90 minutes.

Q: Can I eat before ERCP?

A: No. You must fast for at least 6 hours before the procedure.

Q: Will I be awake during ERCP?

A: You will be sedated — drowsy and comfortable but may not be fully asleep. General anaesthesia is available for anxious patients.

Q: How many sessions of ERCP will I need?

A: Most patients need only one session. Large or multiple stones may require 2 sessions.

Q: Do I still need surgery after ERCP?

A: Yes, in most cases. ERCP removes bile duct stones but not the gallbladder. Laparoscopic cholecystectomy is recommended after ERCP to prevent recurrence.

*Medically reviewed by Dr. Adarsh M Patil, MBBS, MS (General Surgery), Fellowship in Advanced Laparoscopy & Bariatric Surgery (Belgium). Consultant General & Laparoscopic Surgeon, Apollo Clinic Indiranagar, Bangalore.*